Mylyn: http://www.eclipse.org/mylyn/Mylyn can integrate with issue management systems such as Bugzilla, and it also provides context management, which can hide much of the detail of projects that is irrelevant to the task at hand.Mylyn is very helpful, especially your main job is to fix defects, or focus on one component of a big project.

Recently, I re-downloaded and reinstalled jdk, and Eclipse always shows this error:'UnsupportedEncodingException: GBK'. After google search, on http://dev.eclipse.org/newslists/news.eclipse.tools/msg30710.html,
I found out this is because I installed a JRE only for US English, and I should choose to download and install Multi-language JRE.

Problem:

When we save file, it may print out the error "Some characters can not be mapped using GBK character encoding".The solution is to change file encoding to 'utf-8':Select Window -> Preferences ->GeneralSelect Workspace , set Text file encoding to 'utf-8'.Select Content Types, set Default encoding to 'utf-8'

Ignore white space when compare two files in Eclipse IDEWhen compare two files in Eclipse, many times lines differ only in white spaces, and we don't want to notice this minor difference.Solution:Select Window -> Preference -> Compare/Path, and in 'General' tab, select the checkbox --'Ignore white space'.

- Word searchX. Trie + DFS
LeetCode 212 - Word Search II
Given a 2D board and a list of words from the dictionary, find all words in the board.
Each word must be constructed from letters of sequentially adjacent cell, where "adjacent" cells are those horizontally or vertically neighboring. The same letter cell may not be used more than once in a word.https://discuss.leetcode.com/topic/33246/java-15ms-easiest-solution-100-00

LeetCode 30 - Substring with Concatenation of All Words
You are given a string, S, and a list of words, L, that are all of the same length. Find all starting indices of substring(s) in S that is a concatenation of each word in L exactly once and without any intervening characters.

TODOLeetCode 336 - Palindrome Pairs
Given a list of unique words. Find all pairs of indices (i, j) in the given list, so that the concatenation of the two words, i.e. words[i] + words[j] is a palindrome.

LeetCode 630 - Course Schedule III
There are n different online courses numbered from 1 to n. Each course has some duration(course length) t and closed on dthday. A course should be taken continuously for t days and must be finished before or on the dth day. You will start at the 1st day.
Given n online courses represented by pairs (t,d), your task is to find the maximal number of courses that can be taken.

publicintscheduleCourse(int[][] courses){
Arrays.sort(courses,(a,b)->a[1]-b[1]); //Sort the courses by their deadlines (Greedy! We have to deal with courses with early deadlines first)
PriorityQueue pq=new PriorityQueue<>((a,b)->b-a);
int time=0;
for (int[] c:courses)
{
time+=c[0]; // add current course to a priority queue
pq.add(c[0]);
if (time>c[1]) time-=pq.poll(); //If time exceeds, drop the previous course which costs the most time. (That must be the best choice!)
}
return pq.size();
}

LeetCode 373 - Find K Pairs with Smallest Sums
You are given two integer arrays nums1 and nums2 sorted in ascending order and an integer k.
Define a pair (u,v) which consists of one element from the first array and one element from the second array.
Find the k pairs (u1,v1),(u2,v2) ...(uk,vk) with the smallest sums.

Find elements more than K times
Given m sorted lists, find out the elements more than k times. If an element appear more than once in a list, count it only once.
- Use PriorityQueue instead of HashMap to save space

private Bucket head;
private Bucket tail;
// for accessing a specific Bucket among the Bucket list in O(1) timeprivate Map countBucketMap;
// keep track of count of keysprivate Map keyCountMap; or the value can be Bucket// each Bucket contains all the keys with the same countprivateclassBucket {
int count;
Set keySet;
Bucket next, prev;
}